The researchers tested how intermittent aeration in a vertical subsurface flow constructed wetland can improve nitrogen removal from wastewater. By adjusting the ratio of aeration time to non-aeration time, they found that the best nitrogen removal efficiency occurred when the ratio was 3:1. This led to a 12.7% increase in nitrogen removal compared to continuous aeration. However, if the aeration cycle was too long, the efficiency decreased. Overall, the study showed that optimizing aeration in constructed wetlands can enhance nitrogen removal, benefiting wastewater treatment processes.